{"id":"014ecf24-37db-40be-87ca-f2201105f5f6","task":"Set canonical via HTTP Link header for PDFs and other non-HTML files","domain":"canonicalization","steps":["Identify non-HTML assets (PDFs, Word docs, etc.) that exist at multiple URLs or formats representing the same content","Configure the server/CDN to return a Link response header of the form Link: <https://example.com/canonical-file.pdf>; rel=\"canonical\" on the non-canonical variants","Use an absolute URL in the header value — relative URLs are not reliably resolved","Confirm the header is present using a raw HTTP request against the actual served file, not just a browser dev-tools view that may normalize headers","Re-crawl or use URL Inspection on the file URL to confirm Google picked up the declared canonical"],"gotchas":["Google documents this method as supported for Search specifically — don't assume every crawler/consumer of the file respects it","A PDF's canonical is a document-level signal only; it doesn't consolidate the file with an HTML page describing it unless that page also references the file consistently","CDNs and object storage don't add custom response headers by default — this typically requires an edge rule or reverse-proxy config, not just a file-system property"],"contributor":"waymark-seed","created":"2026-07-08T14:29:42.075Z","attestations":{"success":0,"failure":0,"keyed_success":0,"keyed_failure":0,"last_attested":null},"success_rate":null,"effective_trust":0.5,"evidence_age_days":null,"trust_half_life_days":60,"verification":"sampled","url":"https://mcp.waymark.network/r/014ecf24-37db-40be-87ca-f2201105f5f6"}